1. Field of the Invention
The present invention relates to a process for extraction and purification of an antihypertensive agent containing a substance useful for prevention or treatment of hypertension from vegetable oils such as soybean oil, corn oil, rapeseed oil and cotton seed oil, and to a novel substance useful for prevention or treatment of said hypertension.
2. Background Art
Vegetable oils such as soybean oil and the like are generally produced by pulverizing seeds such as soybean seed and then compressing the pulverized seeds at lower temperatures or elevated temperatures. Particularly, soybean oil is produced on a large scale by an extraction method wherein organic solvents such as hexane and the like are used.
However, there has been almost no attempt to effectively utilize the water-soluble components present in the vegetable oils such as soybean oil and the like, and most of the water-soluble components are at present being discarded as waste. Furthermore, to date, almost no investigation has been undertaken to determine structures and properties of the water-soluble components present in these vegetable oils. Some reasons why the water-soluble components present in these vegetable oils are not effectively utilized, are as follows: these water-soluble components present in the vegetable oils comprise extremely various compounds and therefore it is difficult to separate and purify each component, and, moreover, it is difficult to distinguish between useful components and useless components.